Manufacture of carbon conductors



(No Modl.)

T. A. EDISON.

MANUFACTURE OF CARBON GONDUG TORS.

No. 354,310. Patexited Dec. 14,-1 886.

AT TEE T: i INVENTUR:

N, PETERS. mouw n m Wnhlnglom o, r,

IJNITED STATES PATENT OFFICE.

THOMAS A. EDISON, OF MENLO PARK, NEYV JERSEY.

MANUFACTURE OF CARBON CONDUCTORS.

SPECIFICATION forming part of Letters Patent No. 354,310, dated December 14, 1886.

Application filed'April 17, 1883. Serial No. 91,953. (No specimens.) I

To aZZ whom it may concern:

Be it known that I, THOMAS A. EDISON, of Menlo Park, in the county of Middlesex and State of New Jersey, have invented a new and useful Improvement in the Manufacture of Carbon Conductors, (Case No. 556,) of which the following is a specification.

The object of this invention is to produce flexible filaments for incandescing conductors for electric lamps of pure and dense carbon by an artificial process and without the carbonizing of fibrous or other material. By the use of such conductors lamps of high candlepower can be produced. I accomplish this by establishing a voltaic are between two electrodes immersed in a liquid or gaseous compound of carbon decomposable by heat. One of the electrodes must consist of a piece of carbon,while the other should be a rod or wire of metal, carbon, or any conducting mate rial of small area. Carbon from the liquid or gas will be deposited upon the end of the latter electrode, and said electrode is gradually drawn away as this gradual deposit proceeds, the normal length of the are being thus maintained. The negative electrode is preferably of such area that a fine filament is formed. This may be made ofany lengtlnand is of such flexibility that it may, if desired, be bent into loops or horseshoe form.

Enlarged ends for clamping may be formed upon this stick by depositing carbon in any suitable manner.

My invention may be carried into effect by the apparatus illustrated in the annexed drawa is a tank or vessel containing a hydrocarbon oil or other liquid carbon compound capable of being decomposed by heat.

A standard, B, supports the arm 0, which holds the carbon electrode a immersed in the liquid. A screw-threaded rod, D, is supported by the standards B and E, and carries an arm, F, which supports the electrode 1), which is preferably a small platinum rod, but may be of any metal or conducting material. Ahan dle, G, is provided for turning the screw. A guide-rod, H, extendsfrom one standard to the other, and a guide-fork, I, passes along said rod to keep the electrode in position. The wires 1 2 extend to the electrodes from the poles of a dynamo-electric machine, K; or any other suitable electric generator may be employed.

L is a section of insulating'material for preventing a short circuit. An adjustable resistance, M, may be provided for regulating the current supplied to the electrodes.

\Vhen the current is set up and the are established, the heat thereof decomposes the liquid in the vessel, and carbon is deposited upon the electrode 12.

The screw is turned and the electrode 1) is gradually withdrawn. A thin stick or filament of carbon is thus formed, which, when it has attained the desired length, is broken off from the platinum electrode. Enlarged clam ping ends may then be formed upon it in any suitablemanner. The carbon thus produced is of a very pure, dense, and homogeneous struct ure, and is flexible and very suitable for the purpose mentioned.

Instead of the trough containinga hydrocarbon liquid, a vessel may be used through which a decomposable gas is passed, the mechanism for movingthe electrode being actuated by a rod passing into the vessel through a stuffingbox.

Instead of the screw motion sho\vn,anysuitable automatic mechanism-such as is employed in voltaic-arc lamps-may be employed to maintain a constant arc.

It is evident that by using suitable mechan ism for moving the electrode spirals or other shapes of deposited carbon can be formed, and by using electrodes of different areas sticks of different sizes may be produced.

I do not claim herein the product resulting from the process described, this application being limited to the process alone. The product thereof is reserved for a separate application. described apparatus for carrying out my process; but I reserve this also for separate application.

Vhat I claim is 1. Theprocess of forming ineandescing condoctors for electric lamps, consisting in de composing a carbon compound by heat and Neither do I claim herein the abovecausing the carbon set free to deposit in the trode. immersed in a liquid or gaseous carbon required form without any axial cone or supcompound decomposable by heat, and graduport. ally removing one electrode away from the 15 2. Theiprocess of producing carbon sticks other as the stick or filament increases in length or filaments, consisting in establishing a '01- by the deposited carbon, substantially as set taic are between two electrodes immersed in forth.

a liquid or gaseous carbon compound decom- This specification signed and witnessed this posable by heat and maintaining a constant 6th day of April, 1883. length of the are, substantially as set forth.

3. The process of producing carbon sticks orfilaments, consisting in establishing an are between a carbon electrode and another elec- THOS. A. EDISON. Witnesses:

H. W. SEELEY,

EDWARD H. PYATT. 

